3.16.7-ckt15 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Ryan Underwood <neme...@icequake.net> commit 2fb22a8042fe96b4220843f79241c116d90922c4 upstream. Disable write buffering on the Toshiba ToPIC95 if it is enabled by somebody (it is not supposed to be a power-on default according to the datasheet). On the ToPIC95, practically no 32-bit Cardbus card will work under heavy load without locking up the whole system if this is left enabled. I tried about a dozen. It does not affect 16-bit cards. This is similar to the O2 bugs in early controller revisions it seems. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=55961 Signed-off-by: Ryan C. Underwood <neme...@icequake.net> Signed-off-by: Dominik Brodowski <li...@dominikbrodowski.net> Signed-off-by: Luis Henriques <luis.henriq...@canonical.com> --- drivers/pcmcia/topic.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/pcmcia/topic.h b/drivers/pcmcia/topic.h index 615a45a8fe86..582688fe7505 100644 --- a/drivers/pcmcia/topic.h +++ b/drivers/pcmcia/topic.h @@ -104,6 +104,9 @@ #define TOPIC_EXCA_IF_CONTROL 0x3e /* 8 bit */ #define TOPIC_EXCA_IFC_33V_ENA 0x01 +#define TOPIC_PCI_CFG_PPBCN 0x3e /* 16-bit */ +#define TOPIC_PCI_CFG_PPBCN_WBEN 0x0400 + static void topic97_zoom_video(struct pcmcia_socket *sock, int onoff) { struct yenta_socket *socket = container_of(sock, struct yenta_socket, socket); @@ -138,6 +141,7 @@ static int topic97_override(struct yenta_socket *socket) static int topic95_override(struct yenta_socket *socket) { u8 fctrl; + u16 ppbcn; /* enable 3.3V support for 16bit cards */ fctrl = exca_readb(socket, TOPIC_EXCA_IF_CONTROL); @@ -146,6 +150,18 @@ static int topic95_override(struct yenta_socket *socket) /* tell yenta to use exca registers to power 16bit cards */ socket->flags |= YENTA_16BIT_POWER_EXCA | YENTA_16BIT_POWER_DF; + /* Disable write buffers to prevent lockups under load with numerous + Cardbus cards, observed on Tecra 500CDT and reported elsewhere on the + net. This is not a power-on default according to the datasheet + but some BIOSes seem to set it. */ + if (pci_read_config_word(socket->dev, TOPIC_PCI_CFG_PPBCN, &ppbcn) == 0 + && socket->dev->revision <= 7 + && (ppbcn & TOPIC_PCI_CFG_PPBCN_WBEN)) { + ppbcn &= ~TOPIC_PCI_CFG_PPBCN_WBEN; + pci_write_config_word(socket->dev, TOPIC_PCI_CFG_PPBCN, ppbcn); + dev_info(&socket->dev->dev, "Disabled ToPIC95 Cardbus write buffers.\n"); + } + return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
